Recent progress in medical science and engineering has helped to reduce the use of traditional “open body” surgery in which incisions are made to provide access to the operating area within the human body. Minimally invasive therapy, a technique often performed on an outpatient basis without extended hospitalization, is becoming increasingly popular.
Cardiovascular Interventional Radiology, one of the most complex and patient care-oriented fields in radiology, is a medical specialty that uses image-guided, minimally invasive diagnostic and treatment techniques. Because interventional radiologists treat diseases non-operatively, procedures performed by interventional radiologists are generally less costly and less traumatic to a patient than surgery, involving smaller incisions, less pain, and shorter hospital stays. This can lead to improved quality of health care delivery, decreased recovery time and reduced total cost to the patient and health care payors.
Interventional cardiovascular radiology often requires the need to enter the vasculature through small incisions and to utilize medical image guidance to maneuver thin plastic tubes or catheters or other therapeutic or diagnostic devices to a target site in a human body. Most cardiovascular interventional procedures are performed using catheters which are extremely diverse in shape and specific features.
Specific catheter tip shaping generally is required because of the wide variety of sizes and anatomical configurations of blood vessels and because the vascular characteristics of lesion affecting blood vessels vary significantly between individuals. In the 1960s, before the availability of preformed angiographic catheters, Dr. Melvin P. Judkins shaped catheters at the time of each examination by placing a polyurethane tubing over a stiff wire bent to conform to the shape of the blood vessel and then immersing the catheter in boiling water to soften it. When the assembly cooled, he withdrew the wire, and the catheter retained its shape (see, e.g., as described in Dotter and Judkins, 1964, Circulation 30: 654-670; The Catheter Introducers, 1993, Eds: L. A. Geddes and L. E. Geddes, Mobium Press, Chicago, Ill., pp 46; Judkins, 1967, Radiology 89: 815-824). Although there are now many commercially available preformed catheters, clinicians still use steam heating and mandrels to modify the shape of a catheter's tip.
Currently, many years of clinical/design experience and considerable physical prototyping is necessary to create new interventional devices including catheters, guidewires, stents, stent grafts, coils and balloon therapy devices. Customization of devices is still done in an ad hoc fashion.